It is previously unknown that luteinizing hormone or an isoform thereof has an effect of promoting renal growth.
The present inventors concentrated their attention on the fact that hypophysectomized mice would show a significant decrease in the renal weight and decided there might be some factor controlling renal growth in the pituitary. Thus they attempted to find a renal growth factor present in the pituitary. Consequently they obtained a fraction containing a hormone-like component promoting renal growth from the pituitary and named the unisolated component promoting renal growth RGF (or renotropin) (cf. Nippon Rinsho, 44 (1), separate issue, 84-88 (Jan. 1986)).